As Delhi’s air quality continued to be in the ‘severe’ zone for the third day in a row, a three-day ban on construction as well as industrial activities in Delhi-NCR was imposed.
The air quality index value was recorded at 448 on Monday.
According to the SAFAR forecast, air quality will be severe on Tuesday as well. Respite is expected starting Tuesday evening as the wind speed is expected to increase.
Officials at SAFAR said that the long episode of severe to poor air quality was because surface wind speeds are low.
“Radiation fog could not be dissipated because of the low speed of wind. This led to the formation of secondary aerosol formation, which is a cause of increase in finer particulate matter such as PM 2.5 and PM 1. The inversion layer, at 100 m in the early hours on Monday, is also the lowest in the season so far,” the official said.
A low inversion layer also means that there is very little area available for dispersion of pollutants, leading to a concentration of pollutants.
This is the poorest that Delhi’s air has been since Diwali, in November.